Description of problem:
Error message from PREUN scriptlet is not printed from YUM.


Version-Release number of selected component (if applicable):
yum-3.4.3-28.fc17.noarch


How reproducible:
Always


Steps to Reproduce:
1. Try to remove arbitrary package which fails in PREUN with arbitrary error message
  

Actual results:
# yum -y remove VirtualBox-4.1
Loaded plugins: auto-update-debuginfo, langpacks, presto, refresh-packagekit
Resolving Dependencies
--> Running transaction check
---> Package VirtualBox-4.1.x86_64 0:4.1.8_75467_fedora16-1 will be erased

... snip ...

Removing:
 VirtualBox-4.1                  x86_64                  4.1.8_75467_fedora16-1                   @/VirtualBox-4.1-4.1.8_75467_fedora16-1.x86_64/16

... snip ...

Installed size: 114 M
Downloading Packages:
Running Transaction Check
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Error in PREUN scriptlet in rpm package VirtualBox-4.1-4.1.8_75467_fedora16-1.x86_64
  Verifying  : VirtualBox-4.1-4.1.8_75467_fedora16-1.x86_64

Failed:
  VirtualBox-4.1.x86_64 0:4.1.8_75467_fedora16-1


Expected results:
YUM should print error message from PREUN scripts (as RPM does):
# rpm -e VirtualBox-4.1
A copy of VirtualBox is currently running.  Please close it and try again.
Please note that it can take up to ten seconds for VirtualBox (in particular
the VBoxSVC daemon) to finish running.
error: %preun(VirtualBox-4.1-4.1.8_75467_fedora16-1.x86_64) scriptlet failed, exit status 1
error: VirtualBox-4.1-4.1.8_75467_fedora16-1.x86_64: erase failed